Selling s**** to customers

Bought a washing machine from the shop 2 weeks ago,it ended up being faulty got send back for the so called repair warrenty only to come back a week later and still not working,the tech guy does not know what is wrong with it,. The shop will only refund me instead off giving me a working machine which i had payed for, it is not acceptable as the wife was very happy to get a so called good working machine only to be left dissapointed with a big shop like cash crusaders